Method of and apparatus for determining furnace temperatures



FURNACE TEMPERATURES Filed May 19, 1961 D. E. CARNEY METHOD OF AND APPARATUS FOR DETERMINING I l I ATTORNEYS United States Patent 3,160,009 METHOD GF AND APPARATUS FOR DETER- MTNENG FIRNACE TEMPERATURES Delmar E. Carney, Toledo, Ohio, assignor to Libbey- Owens-Ford Glass Company, Toledo, Ohio, a corporation of @hio Filed May 19, 1951, Ser. No. 111,261 4 Claims. (Ql. 73355) The present invention relates broadly to the temperature control of melting furnaces and is more particularly concerned with an improved method of and apparatus for determining the temperatures of furnaces;

It is an important object of this'invention to provide a method for determining furnace temperatures which will peratures within the melting zones of the furnace while at the same time having a longer service life than recording devices heretofore used for this purpose. I

Anotherobject of the invention is to provide apparatu for carrying out the method described above which apparatus is never entirely exposed to the high internal temperatures of the furnace but which provides accurate readings of the temperatures substantially continuously during the normal operations of the furnace.

Other objects and advantages ofthe invention will become more apparent during the course of the following description when taken in connection with the accompanying drawings.

In the drawings, wherein like numerals are employed to designate like parts throughout the same:

FIG. 1 is a fragmentary horizontal cross-section of a glass-melting tank furnace, which with the method of this invention can be practiced;

FIG. 2 is a transverse .vertical section takenon line 2-2 of FIG. 1;

FIG. 3 is an enlarged sectional view of a temperature recording device as mounted on a vertical side wall of the furnace; and

FIG. 4 is a diagrammatic view of an electrical circuit by which the apparatus functions with the normal controls employed with the furnace.

3,16%,M9 Patented Dec. 8, 1964 cycles. To illustrate, when the burners of ports have operated for a predetermined period of time, during which the hot exhaust gases pass through the ports 16, the supply. of gas is shut off and, after an interval of time, gas is supplied to the burners of ports 16 in a reversing cycle.

' In this manner, the flow of fresh air to the burners in For purposes of illustration, the present invention is illustrated in the drawings embodied .in a glass-melting tank furnace 19 of the regenerator type which is fired by flames alternately originating at. the opposite side walls 11 and 12 of the furnace. For this purpose, the side walls 11 and 12 are each equipped with a plurality of socalled burner ports 15 and 16 which at their outwardly directed ends are connectedto regenerator chambers as indicated at 17 on one side of the furnace. vIn the illustrated furnace, five such ports are provided at each side of the furnace and are arranged side by side with corresponding ports at the opposite sides .being opposed to each other.

conventionally speaking, glass batch materials are introduced into the furnace 10 through an end wall 13 from a supply area 14, usually termed the doghouse, and I move lengthwise through the furnace 'past the burner ports where they are heated and reduced to a molten state. After the batch materials are reduced to a molten mass, the latter is gradually worked from the actual melting zone at one end of the furnace to a refining zone adjacent the opposite end.

To produce the necessary heatenergy to melt and refine the glass, gas is supplied to suitable burners (not shown) arranged in each of the ports 15 and 16 and air to support combustion of the gas is obtained through the ports from the regenerator chambers 17. Thus the gaseous flames emanating from the burner ports 15 will carry across the zones of the furnace above the molten glass and exhaust 1 afford a more pos1t1ve recording of extremelyhigh temports 16 will be heated by the residual heat in the associated regenerator. Also, as the exhaust gases of the flames from the burners in ports 16 pass through the I ports 15 they enter and similarly transmit heat to the associated regenerator chamber 17.

Usually the heat created by the burners in any of the several ports 15 or 16, arranged in aligned relation across the furnace, is controlled in thermal output to provide diminishing temperatures from the doghouse area toward the refining area. Thus, in the first or initial firing zone, to obtain relatively rapid reduction of the glass batch materials into the molten mass, the temperature main.- tained may reach a range of 3000" F. while in the adjoining zones, the temperature ranges will be lowered until in the zone of the fifth or last ports15 and 16, the range would be in the vicinity of 270( F. These extremely high temperatures are, of course, very destructive to even the most carefully protected instruments and as a consequence continuously accurate information as to such temperatures is unpredictable and the instruments themselves have a relatively short service life.

One heretofore employed manner of obtaining tempera tures has been to install thermocouples or like instruments in the cap or roof arch 20 of the furnace, as indicated at 21 in FIG. 2 and to enclose them in a refractory enclosure 22. However, as explained above, the high temperature in the upper area of the furnace or as absorbed in the roof structure, rapidly acts upon the reading elements of such rather delicate instruments to the end that the information gained thereby becomes progressively more inaccurate and eventually the instru- 'rnent's deteriorate to a point of complete failure.

It is herein proposed to obtain a record of such temperatures from a source located outside of .the actual firing area thereby protecting the instruments from relatively continuous exposure to high heat while at the same time obtaining such temperature readings and recording them in a convenient and substantially continuous manner. For this purpose, a heat reading meter 23 which may be of the pyrometer type is mounted on a pedestal 24' on the floor area 25 closely adjoining any of the walls 11, 12 or 13 of the furnace. As shown in FIG. 1, one of these meters is so positioned as to determine the temperature of a furnace zone between the line a and line b. The" meter is so mounted that the line of focus will be directed toward a central area of the roof arch 20 as indicated by line 0 in FIG. 2. A shutter panel 27 is arranged on the respective wall of the furnace to alternatively expose or obscure'the area-of anopening 28 provided in the wall. As shown in FIG. 3, one way of operating the shutter or door 27 is .to mount the same in a slide frame 29 and connect the piston rod 30 of 'a cylinder 31 thereto. Equivalent devices, such as solenoids or the like can be employed to equal advantage. In any event the energy supplied to the cylinder to operate the panel can be by an air valve 32 which is included in a control system shown in FIG. 4. V

The control system includes an electric source 35 connected through switch 56 and by line 37 to a control panel 38 which includes instrumentalities adapted to complete a circuit by line 39 to the necessity burner controls and supply valves for the burners of ports and by line 40 to the similar supply system for the burners of ports 16. The control panel 38 is also. connected by line 41 to a timing device 42 which is connected by line 43 to the opposite source 44. I The timing device 42'by line 45 activatesthe meter 23 and by branch 46 an electrically operated and automatically reversing valve such as the .valve 32, which connects a source of air under pressure through the pipe 48 (FIG. 3)- to the lower end of cylinder 31. The necessary circuits of meter- 23 and valve 32 may be completed to source 44 by line connections 49 and 50.

The circuit of the meter 23, which is dependent upon the timer 42' for its completion, is connected by line 51 to a conventional dial recording device 52. As is well known, such recording devices are provided with graph paper charts that are mounted so as to be slowly turned according to a desired time cycle and with a pen adapted to traverse the chart and thus record on said chart the temperatures read by the meter 23.

In operation, during therelatively short interval of time between the alternating cycles of cross-firing at the I furnace ports 15 and 16, the functioning elements of the control panel 38 will complete a circuit by line 41 to the timing device 42.. This'will actuate the valve 32 to lift the shutter 27 upon pressure being supplied through pipe 43 to the cylinder 31 and substantially simultaneously complete the; circuitry of meter 23 which throughline 51 will cause the pen of recording device 52 to reproduce the degree of temperature obtained by the meter from the furnace walls or arch. Thisrecording is of course made between the reversal of firing and consequently there will be no turbulence of flameto, interfere with an accurate reading ofv the temperature.

by the peak p of the graph line.

graph line toa dwell d during which the pen will maintain a substantially continuous line; said dwell having a length equal to the period during which the firing of the furnace is carried out. In asubsequent reversal in the alternating cycle, the control panel 38 will first shut oif .one set of'burners, then operate the meter 23, as indicated by the next peak line, and finally complete the circuits to the controls for the opposite set-of burners. .This will resultinobtaining accurate information as to furnace temperature in a continuous manner of operation and with the temperature reading device protected-from damage by the flames producing such temperatures.

It is to be understood that the form-of-the invention herewith shown and described is to be taken as an illus- By way of example, the furnace temperature in one area would thus be indicated Then 'as the oneset of burners or 'the other begin operation, the timer,- will deactivate with resulting closure of the opening 28;- by shutter 27. This will be denoted by a drop in the trative embodiment only of the same, and that various changes in the shape, sizeand arrangement of parts, as

.well as various procedural changes maybe resorted to sensing device whereby the latter senses the temperatures within the chamber and produces a signal'in accordance therewith, synchronizing the exposure of the temperature sensing device and the actuation of the device with the operation of the burners whereby the device is exposed and actuated only when the burners are in the ofl'cycle and recording the temperature sensed by the sensing device in rmponse to the signals produced by the device.

2. ,In apparatus for measuring andrecording temperatures within a chamber defined by top, bottom and side walls and heated by flames directed into said chamber from burners operated in alternating, timed oft-on cycles, a heat reading meter disposed outside said chamber and exposed to the interior of thechamber through an openingformedin one of said side walls, a shutter means slidably' mounted on said one sidewall adjacent said opening, actuator means operatively coupled to said shutter.

means to slide the shutter means along a fixed path toward and awayfrom said opening thereby to' selectively cover-and uncover theopening, control means synchronizing the operation of said heat reading meterand said actuator with the'operation. of said burners, whereby said shutter is slid away from said opening and said meter reads the temperature of the interior of said chamber only when said burners are-in said oif cycle and means recording said temperatureread. by said meter.

3. In apparatus for measuring andrecording temperatures within-a chamber as defined by claim 2,, wherein said actuator means comprises a piston connected to said shuttermeans and slidablein a cylindermounted on said oneside wall, azv'alve means operable to introduce pressure fluid selectively to opposite ends of said cylinder, said valve means being actuated by said second control means.

4; In apparatus for measuring and recording temperatures within a furnace'having a heating chamber defined by top, bottom and side walls and heated by flames directed into the chamber from first burners disposed adjacent'one of said side walls and alternately from second burners disposed adjacentan opposed sidewall, said first and second burners being operated in. alternating sequences whereby said-flames are directed to said chamber from first one set of'burners' and then the opposite set of burners, a heat reading meter disposed outside said heating chamber and exposed 'to the interior of the chamber through an opening formed in one of said side walls, shutter means mountedron said one side Wall adjacent said opening, actuator means operatively coupled to said shutter means to slide the'shutter means along a fixed path toward an'daway from said opening to selectively cover and uncover the opening, control means synchrouizing'the operationof said heat reading meter and said actuator with the operation of said first and second burners whereby the shutter slid away from said'openperature Within said? chamber only during an interval after one of said burners ceases to operate and before the other of said burnerscommences to operate and means recording the temperature sensed by said heat reading meter. 9

References Cited in the file of this patent UNITED STATES PATENTS 2,127,889 Shenk Aug. 23, 1938 2,133,045 Rurnford Oct. 11, 1938 2,177,805 Hogg'et a1. Oct. 31, 1939 2,531,200 Davis Nov. 21, 1950 

1. IN A METHOD OF MEASURING AND RECORDING TEMPERATURES IN AN ENCLOSED CHAMBER HEATED BY FLAMES INTERMITTENTLY DIRECTED INTO SAID CHAMBER FROM BURNERS OPERATED IN ALTERNATING, TIMED OFF-ON CYCLES, THE STEPS OF INTERMITTENTLY EXPOSING A TEMPERATURE SENSING DEVICE DISPOSED OUTSIDE OF THE HEATING CHAMBER TO THE INTERIOR OF THE CHAMBER, INTERMITTENTLY ACTUATING THE TEMPERATURE SENSING DEVICE WHEREBY THE LATTER SENSES THE TEMPERATURES WITHIN THE CHAMBER AND PRODUCES A SIGNAL IN ACCORDANCE THEREWITH, SYNCHRONIZING THE EXPOSURE OF THE TEMPERATURE SENSING DEVICE AND THE ACTUATION OF THE DEVICE WITH THE OPERATION OF THE BURNERS WHEREBY THE DEVICE IS EXPOSED AND ACTUATED ONLY WHEN THE BURNERS ARE IN THE OFF CYCLE AND RECORDING THE TEMPERATURE SENSED BY THE SENSING DEVICE IN RESPONSE TO THE SIGNALS PRODUCED BY THE DEVICE. 